Cynodon dactylon plant named `Riley&#39;s Super Sport`

ABSTRACT

A new variety of Cynodon dactylon exhibiting prostrate growth, short internode length, minimal seed head production and deep green coloration.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct Cynodon dactylonvariety.

The new variety is the result of a spontaneous mutation of the Cynodondactylon variety `Greenlees Park` (unpatented) and was propagatedvegetatively through four generations. The varietal denomination of thenew variety is `Riley's Super Sport`.

There is an ongoing need in the United States for turf grass varietieswhich are hard wearing, low in maintenance and which provide good groundcover and attractive grass color. Such varieties find particular use onplaying fields, golf courses, bowling greens, parks, as well as indomestic and commercial settings.

The parent of `Riley's Super Sport`, `Greenlees Park`, is widely used inthe United States, such as in the California area, on golf courses attees and on fairways. As described hereinafter `Riley's Super Sport` isan advantageous turf grass species in many respects over and abovecommercial turf grass species.

SUMMARY OF THE INVENTION

The new variety of Cynodon dactylon, `Riley's Super Sport`, exhibits avery prostrate growth habit thereby having minimal vertical growth (thatis, very prostrate growth habit), extensive leaf production, shortinternode length, very low seed head production, and deep greencoloration, amongst other characteristics herein described whichdistinguish the subject variety from presently available commercial turfgrass varieties. Under moderate climatic conditions such as coastalareas of California, green color quality can be maintained throughoutthe year. The new variety is vegetatively propagated from sod, plugs,tillers or stolons and rhizome pieces. Asexual propagation by rhizomesand tillers at the Australian Turf Grass Research Institute in Sydney,New South Wales, Australia has demonstrated that the combination ofcharacteristics of the new variety are transmitted through succeedingpropagations.

`Riley's Super Sport` differs from `Greenlees Park` in having a veryprostrate growth habit, extensive leaf production, leaf dimensions, leafcolor, short internode length, and minimal seed head production.

BRIEF DESCRIPTION OF ILLUSTRATIONS

The accompanying illustrations show typical specimens of the vegetativegrowth of the new variety.

FIG. 1: shows turf appearance of the new variety in use at bowlinggreen, with the bank (left hand side of the Figure) cut at 6 mm height,and the green (right hand side of the Figure) cut at 1 mm height.

FIG. 2: shows six months growth of the new variety cultivated in plantpots.

FIG. 3: shows six months growth of the comparative variety `GreenleesPark` cultivated in plant pots.

FIG. 4: shows six months growth of the comparative variety `WindsorGreen` (unpatented) cultivated in plant pots.

FIG. 5: shows a close up of isolated stolons of the new variety andcomparative varieties `Windsor Green` and `Greenlees Park`

FIG. 6: shows the growth habit of the new variety.

DESCRIPTION OF THE NEW VARIETY

The description of color is by reference to The Royal HorticulturalSociety Colour Chart.

The new variety `Riley's Super Sport` is a spontaneous mutation of thevariety `Greenlees Park`. It forms a dense turf that spreads by way oftillers, stolons and rhizomes.

The new variety has a very prostrate growth habit with a medium lateralextension rate and high node density.

Leaf blades are of yellow green coloration, R.H.S. 147A. Mean leaflength is 8 mm, mean leaf width is 1.7 mm and the mean leaf length:widthratio is 5/1.

Stolons of `Riley's Super Sport` are red/purple, are of high density,with a short internode length having a mean of 13.6 mm.

Winter growth of `Riley's Super Sport` is low, with an unmown heightover winter having a mean of 8 mm.

The new variety is vegetatively propagated from sod, plugs or stolon orrhizome pieces. It performs best in full sun, but also grows well inshade. It is hard wearing and has an easily controllable mat densitywhich is responsive to mowing management in order to provide a hardsurface, for use such as in bowling greens, or a soft surface for usesuch as in parks, on golf fairways, or in domestic situations. Indrought conditions the new variety recovers quickly on application ofwater. As a consequence the turf formed from the new variety is suitablefor situations requiring a durable, high quality lawn that is tolerantof heat and drought stress. As previously mentioned, such applicationsinclude parks, golf courses, bowling greens, domestic lawns, and publicplanting areas. The accompanying illustrations serve to illustrate thedistinctive features of the new variety. As can be seen from FIG. 1 thevariety can be finely cut, such as 1 mm height, to provide a dense matof prostrate growth habit for use as a bowling or putting green, or cutat a greater height, such as 6 mm to provide a durable walking surface,such as the verge of a bowling green, golf fairway and many other suchapplications. FIGS. 2 to 4 show growth of the new variety `GreenleesPark` and `Windsor Green` after six months in plant pots, cultivated inSydney, New South Wales, Australia, under ambient conditions. As isclearly evident from these figures, the new variety shows compact growthwith little vertical extension. The new variety is a low lying grass incontrast with the marked vertical extension of the comparative varieties`Greenlees Park` and `Windsor Green` . FIG. 5 shows stolons of the newvariety, `Greenlees Park` and `Windsor Green`. The new variety isclearly distinguished from the comparative varieties on the basis ofinternode length (much shorter as shown) with consequent leaf density.FIG. 6 shows the morphology of the new variety in vivo, that is, growingin the ground. The principal features of stolon, leaf and internodelength are clearly observable.

To further illustrate the differences between the new variety `Riley'sSuper Sport` and the variety `Greenlees Park` tests were conducted atthe Australian Turf Grass Research Institute, New South Wales, fromOctober 1995 through to March 1996. Thirty stolons were used toestablish each grass variety in sandy soil in pots in the open usingstandard turf grass management practices. A hundred samples of eachvariety were measured for internode length, stolon thickness, leaflength and width. Twenty measurements were made for unmown sward, andten grid counts for seed head density. The results of these evaluationsare shown in Table 1. In this test the variety `Windsor Green`, anotherturf grass variety, was also included.

Statistical differences among the cultivars were determined according tostandard statistical tests. `Riley's Super Sport` had a very prostrategrowth habit compared with a bunched growth habit of `Windsor Green` anda prostrate growth habit of `Greenlees Park`. Node density of `Riley'sSuper Sport` was very high (mean internode length being 13.6 mm)compared to a high node density of `Windsor Green` (mean internodelength 40.2 mm), and a medium to high medium node density of `GreenleesPark` (mean internode length 28.9 mm). The significant difference ininternode length of the new variety, compared to the comparativevarieties results in a greater abundance of leaf (as leaves are producedat nodes) and hence density of ground cover.

The mean uncut sward height (11.7 mm), leaf length (8 mm), leaf width(1.7 mm), and leaf length:width ratio (5/1) shown in Table 1 clearlydifferentiates `Riley's Super Sport` from the varieties `Windsor Green`and `Greenlees Park`. This combination of characteristics associatedwith high density, short internode length (mean 13.6 mm) stolonsprovides a high density turf of pleasant appearance providing excellentground cover with minimal vertical growth.

Seed head production was extremely low, having a mean number of seedheads being 0.2/100 cm2 for the subject variety, compared to a mean of2.5/100 cm 2 for `Windsor Green`, and a mean of 4.0/100 cm2 for thevariety `Greenlees Park`. The very low seed head production of thevariety `Riley's Super Sport` gives an attractive appearance of the turfand decreases the need for mowing to remove seed heads. Where seed headsare allowed to produce flowers, the anther color is red purple (64B).`Riley's Super Sport` is a turf grass variety of Cynodon dactylon havingthe adorementioned features which distinguish it from the variety`Greenlees Park`. The subject variety has additional characteristics of:leaves folded in bud shoot; short leaf blade (8mm), keeled and acuminateat the tip; leaf blade margin ciliate; absence of auricle; very low seedheads (0-2/100 cm²) with generally 3 to 5 spikes which are up to 2.5cmlong; spikelets up to 2mm long; stolons present with a width of 1.3mm;rhizomes present with a width a 1.6mm. The subject variety containsother standard characteristics of Cynodon dactylon varieties which dodistinguish it from, and are common to, other Cynodon dactylonvarieties, particularly culm, glume, sheath and lemma.

Lateral extension rate of `Riley's Super Sport` was measured against`Greenlees Park` over 14 days. Measurements were taken on pioneerstolons of 5cm length growing from 100mm diameter plugs. The area aroundthe plug was divided into 8 equal sectors. The longest stolon in eachsector was measured. Four replicate plugs of each grass were used inmeasurements. Mean lateral extension rate is as follows:

    ______________________________________                                        Grass          Lateral extension rate (cm)                                    ______________________________________                                         `Riley's Super Sport`                                                                       10.4                                                           `Greenlees Park`                                                                                            13.5                                            ______________________________________                                    

The new variety exhibits no unusual resistance or susceptibility topests or diseases as compared to the species.

                  TABLE 1                                                         ______________________________________                                        Cynodon Varieties                                                                      Riley's Super                                                                          Windsor     `Greenlees                                               Sport`              Green`                                                                                 Park`                                   ______________________________________                                        PLANT                                                                         habit                        bunchede                                                                                  prostrate                            lateral                                                                       extension                                                                     rate                        slow to medium                                                                       medium to high                             node density                                                                                  very high                                                                              high               medium                            mean                                                                          internode                                                                     length                13.6 mm                                                                            40.2 mm                                                                                      28.9 mm                             UNCUT SWARD                                                                   HEIGHT (mm)                                                                   mean                            87.2                                                                                      21.8                              std deviation                                                                                0.95             8.52                                                                                       2.87                             LSD/sig              8.40                                                                               p ≦ 0.01                                                                           p ≦ 0.01                         LEAF LENGTH                                                                   (mm)                                                                          mean                              14.7                                                                                     11.7                             std deviation                                                                                0.29              1.13                                                                                      0.34                             LSD/sig              1.58                                                                                p ≦ 0.01                                                                           p ≦ 0.01                        LEAF WIDTH                                                                    (mm)                                                                          mean                                         1.8                              std deviation                                                                                0.03              0.04                                                                                     0.06                              LSD/sig              0.07                                                                                p ≦ 0.01                                                                           p ≦ 0.01                        LEAF                                                                          LENGTH:WIDTH                                                                  RATIO                                                                         mean                              12/1                                                                                      7/1                             std deviation                                                                                0.2                1.7                                                                                        0.1                            LSD/sig              1.41                                                                                 p ≦ 0.01                                                                          p ≦ 0.01                        LEAEF COLOR                                                                   (RHS)                      green 137B                                                                               yellow green                            colour                147A                                                                                                 147B                             SEED                                                                          HEADS/100 cm2                                                                 mean                                           4.0                            std deviation                                                                                0.4                             0.9                            LSD/sig              1.13                                                                                  p ≦ 0.01                                                                          p ≦ 0.01                       ______________________________________                                    

As mentioned above `Riley's Super Sport` is vegetatively propagated fromsod, plugs, tillers or stolons and rhizome pieces. The new variety haswide application due to its desirable properties herein described.

I claim:
 1. A new and distinct variety of Cynodon dactylon plant named `Riley's Super Sport`, substantially as described and illustrated. 